The two goals in the medical management of aortic dissection are to reduce blood pressure and to reduce the oscillatory shear on the wall of the aorta (the shear-force dP/dt or force of ejection of blood from the left ventricle). The target blood pressure should be a mean arterial pressure (MAP) of 60 to 75 mmHg.
Step 1: Rate Control
The initial step in the medical management of the patient with aortic dissection is rate control. Rate control reduces oscillatory sheer stress as well as blood pressure. Rate control should be accomplished before vasodilators are administered in so far as vasodilators can increase oscillatory sheer stress.
Intravenous beta blockers can be administered and titrated to a heart rate of 60 bpm or less. Labetalol is an ideal agent in so far as it has both alpha and beta blocking properties.
If there is an absolute contraindication to the administration of beta blockers than a nondihydropyridine calcium channel–blocking can be administered as an alternative for rate control. The calcium channel blockers typically used are verapamil and diltiazem, because of their combined vasodilator and negative inotropic effects.
If aortic insufficiency is present, then beta blocker administration should be undertaken carefully as prolonging the diastolic filling period may increase the magnitude of aortic regurgitation.
Step 2: Blood Pressure Control
Vasodilator administration should only be undertaken after the heart rate is controlled. If the heart rate is not controlled, the administration of vasodilators may cause reflex tachycardia, and cause further expansion of the dissection.
If the systolic blood pressure remains above 120 mm Hg, then an angiotensin-converting enzyme inhibitor should be administered to further reduce the blood pressure. If this is ineffective, then the administration of parenteral vasodilators should be considered.
If the individual has refractory hypertension (persistent hypertension on the maximum doses of three different classes of antihypertensive agents), involvement of the renal arteries in the aortic dissection plane should be considered.
Medical Management Versus Surgical Management
ACC/ AHA Guidelines - Recommendations for the Initial Management of Aortic Dissection (DO NOT EDIT)
1.Initial management of thoracic aortic dissection should be directed at decreasing aortic wall stress by controlling heart rate and blood pressure as follows:
a. In the absence of contraindications, intravenous beta blockade should be initiated and titrated to a target heart rate of 60 beats per minute or less. (Level of Evidence: C)
b. In patients with clear contraindications to beta blockade, nondihydropyridine calcium channel–blocking agents should be utilized as an alternative for rate control.(Level of Evidence: C)
c. If systolic blood pressures remain greater than 120 mm Hg after adequate heart rate control has been obtained, then angiotensin-converting enzyme inhibitors and/or other vasodilators should be administered intravenously to further reduce blood pressure that maintains adequate end-organ perfusion. (Level of Evidence:C)
d. Beta blockers should be used cautiously in the setting of acute aortic regurgitation because they will block the compensatory tachycardia (Level of Evidence:C)
1.Vasodilator therapy should not be initiated prior to rate control so as to avoid associated reflex tachycardia that may increase aortic wall stress, leading to propagation or expansion of a thoracic aortic dissection (Level of Evidence: C)
ACC/ AHA Guidelines - Recommendations for the Definitive Management of Aortic Dissection (DO NOT EDIT)
1. Urgent surgical consultation should be obtained for all patients diagnosed with thoracic aortic dissection regardless of the anatomic location (ascending versus descending) as soon as the diagnosis is made or highly suspected (Level of Evidence: C)
2. Acute thoracic aortic dissection involving the ascending aorta should be urgently evaluated for emergent surgical repair because of the high risk of associated life-threatening complications such as rupture. (Level of Evidence: B)
3. Acute thoracic aortic dissection involving the descending aorta should be managed medically unless life-threatening complications develop (e.g., malperfusion syndrome, progression of dissection, enlarging aneurysm, inability to control blood pressure or symptoms) (Level of Evidence: B)
ACC/ AHA Guidelines - Recommendations for Medical treatment of patients with Thoracic aortic diseases (DO NOT EDIT)
1. Stringent control of hypertension, lipid profile optimization, smoking cessation, and other atherosclerosis risk-reduction measures should be instituted for patients with small aneurysms not requiring surgery, as well as for patients who are not considered surgical or stent graft candidates (Level of Evidence: A)
ACC/ AHA Guidelines - Recommendations for Blood pressure control in Thoracic aortic disease (DO NOT EDIT)
1.Antihypertensive therapy should be administered to hypertensive patients with thoracic aortic diseases to achieve a goal of less than 140/90 mm Hg (patients without diabetes) or less than 130/80 mm Hg (patients with diabetes or chronic renal disease) to reduce the risk of stroke, myocardial infarction, heart failure, and cardiovascular death. (Level of Evidence: B)
2.Beta adrenergic–blocking drugs should be administered to all patients with Marfan syndrome and aortic aneurysm to reduce the rate of aortic dilatation unless contraindicated. (Level of Evidence: B)
1.For patients with thoracic aortic aneurysm, it is reasonable to reduce blood pressure with beta blockers and angiotensin-converting enzyme inhibitors or angiotensin receptor blockers to the lowest point patients can tolerate without adverse effects. (Level of Evidence:B)
2.An angiotensin receptor blocker (losartan) is reasonable for patients with Marfan syndrome, to reduce the rate of aortic dilatation unless contraindicated. (Level of Evidence:B)
ACC/ AHA Guidelines - Recommendations for Dyslipidemia in aortic dissections (DO NOT EDIT)
1. Treatment with a statin to achieve a target LDL cholesterol of less than 70 mg/dL is reasonable for patients with a coronary heart disease risk equivalent such as noncoronary atherosclerotic disease, atherosclerotic aortic aneurysm, and coexistent coronary heart disease at high risk for coronary ischemic events (Level of Evidence:A)
ACC/ AHA Guidelines - Recommendations for smoking cessation in Thoracic aortic disease (DO NOT EDIT)
1. Smoking cessation and avoidance of exposure to environmental tobacco smoke at work and home are recommended. Follow-up, referral to special programs, and/or pharmacotherapy (including nicotine replacement, buproprion, or varenicline) is useful, as is adopting a stepwise strategy aimed at smoking cessation (the 5 As are Ask, Advise, Assess, Assist, and Arrange) (Level of Evidence: B)
